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Re: Cool White vs Neutral white

Originally Posted by Illum

very well, then how your you explain the dramatic increase in color rendition due to warmer tints?

Even without the increase in CRI, a warm led can seem like it renders color better due to which colors it renders well. To make matters even more complicated, between your eyes and your brain, a large amount of compensation can take place. The amount of compensation varies from person to person, so it's awfully difficult to create a standard for it.

While CRI is a good base measure, it doesn't account for how people perceive light. IIRC, to achieve the full 100 CRI, there must be included wavelengths of light that human eyes can't even see. I've read that there's a better system in the works, but who knows when/if it will ever be put into use.

Due to my current schedule being pretty darn hectic, I will not be accepting new modding projects until things settle down.

Re: Cool White vs Neutral white

Originally Posted by Tekno_Cowboy

Even without the increase in CRI, a warm led can seem like it renders color better due to which colors it renders well. To make matters even more complicated, between your eyes and your brain, a large amount of compensation can take place. The amount of compensation varies from person to person, so it's awfully difficult to create a standard for it.

While CRI is a good base measure, it doesn't account for how people perceive light. IIRC, to achieve the full 100 CRI, there must be included wavelengths of light that human eyes can't even see. I've read that there's a better system in the works, but who knows when/if it will ever be put into use.

Re: Cool White vs Neutral white

Very nice pictures! Especially the one looking down the barrels. The reflection off the reflector really shows off the differences in phosphor application between emitters.

Originally Posted by Illum

very well, then how your you explain the dramatic increase in color rendition due to warmer tints?

There's a little gain in CRI from the additional phosphorescent conversion, though it's not the driving factor.

The output spectrum is shifted towards generally more "useful" colours even though it remains unevenly distributed. Chiefly important are the reds and browns, which are very common in every day objects (especially outdoors). Green output remains good on warmer emitters and your eyes are especially sensitive to that wavelength anyway. Blue drops off a bit, but since the LED naturally has a gigantic spike of that wavelength this isn't necessarily a bad thing.

Re: Cool White vs Neutral white

Even with compensation, your eyes still work better under the right lighting conditions.

In bright light, cool light works fine, and it's similar to daylight. But in low lighting, neutral tints are better on the eyes.

I can only stand to read for a few minutes using cool white LED light. But if I use warm LED light, I can read for an hour or more without sore eyes or a headache.

This is why the majority of lighting for residential use is warm/soft white. It's what works best with the human eye when the pupil is dialated at moderate lighting levels.

Everything is pretty much true here except the last part. At typical residential lighting levels in the 100 to 500 lux area 3500K to 4100K is the sweet spot for most people according to the Kruithof curve. This is more or less where most neutral LED tints fall.

Re: Cool White vs Neutral white

Originally Posted by Illum

very well, then how your you explain the dramatic increase in color rendition due to warmer tints?

To add to what a few others said, a warmer tinted LED basically increases contrast if you're viewing a scene heavy in warm colors. And contrast is actually what our vision is based on to a large extent. That doesn't necessarily mean it has better color rendering overall, or that the colors are more accurate. It just means you can distinguish between subtle shades of warmer colors more easily than with a cooler LED. In a scene heavy with neutrals or cooler colors, the warm LED would actually be worse. What it all boils down to is to use the right tool for the job. If you're viewing a typical cityscape, a cool LED works best. If you're looking at nature, a warm or neutral one would. If you're looking at something in between, it probably boils down to your preferences.

Re: Cool White vs Neutral white

Originally Posted by jtr1962

Everything is pretty much true here except the last part. At typical residential lighting levels in the 100 to 500 lux area 3500K to 4100K is the sweet spot for most people according to the Kruithof curve. This is more or less where most neutral LED tints fall.

CRI difference?

Last week I received my two purple Maglites, a 2D and a 3D. These are not really the same colour, because Maglite has at least two different shades of purple, and I got one of each. When looking at them under cool LED-light they appear as very identical. But under incandescent light like the home light bulbs and MagCharger the difference is significant. Look at these two photos and you will see it clearly.
Also I later compared with my EagleTac M2XC4 neutral white, and the difference was significant compared to P7 LED, but not that significant as with MagCharger.
I understand this remarkable difference is an example of the difference of CRI? Edit: at request I also took a picture with EagleTac M2XC4 neutral white as light source. This actually made me surprised. The difference of the photo is much less than what I actually experience with my eyes.According to the photo it's closer to the cool white LED, but according to my LIVE view it's closer to the incan...Anyway; incandescent light is superior when it comes to true colour rendition!

Re: CRI difference?

Very interesting/informative pictures swedpat! Please post a pic under a neutral LED too
Somewhere I have a pic of cool vs neutral LED with my Raw NS/Raw AL and the difference is also quite noticeable like this, I will try to find it.

Re: CRI difference?

Originally Posted by Swedpat

Last week I received my two purple Maglites, a 2D and a 3D. These are not really the same colour, because Maglite has at least two different shades of purple, and I got one of each. When looking at them under cool LED-light they appear as very identical. But under incandescent light like the home light bulbs and MagCharger the difference is significant. Look at these two photos and you will see it clearly.
Also I later compared with my EagleTac M2XC4 neutral white, and the difference was significant compared to P7 LED, but not that significant as with MagCharger.
I understand this remarkable difference is an example of the difference of CRI?

Re: CRI difference?

very nice pics!
and, your comment below intrigues me...

what camera settings did you use?
perhaps the settings needs to be tweaked further to get a closer representation in pic to what your eye sees? (this is same battle I am fighting to create the pics for the comparision link in my sig below - I think I have it close now with a custom setting, but it could certainly always be improved upon)
cheers

Originally Posted by Swedpat

...Edit: at request I also took a picture with EagleTac M2XC4 neutral white as light source. This actually made me surprised. The difference of the photo is much less than what I actually experience with my eyes.According to the photo it's closer to the cool white LED, but according to my LIVE view it's closer to the incan...Anyway; incandescent light is superior when it comes to true colour rendition!
...

the reality of life... 50% +/- of it will be in darkness(unless you have a light!) dba - compare lights

Re: Cool White vs Neutral white

Thanks lebox97,

If you with setting mean white balance, the setting was on AUTO when I took these pictures. It's also another setting which calls "colour level(or position, don't know what is the best word)" (directly translated from swedish) and this is on NORMAL.

Re: Cool White vs Neutral white

Just a note. Auto white balance tends to try and correct things to daylight standard. If you want the picture to be a better match to what you see, try setting to daylight white balance. THis will show you the differences in colour for each beam.

Re: Cool White vs Neutral white

+1
when camera is set for auto - it makes adjustments for light, focus, ISO everything based on the light output - so for our purposes the results will be skewed...

I have not tried daylight balance though - I'll give it a "shot"

QUOTE=gunga;3094230]Just a note. Auto white balance tends to try and correct things to daylight standard. If you want the picture to be a better match to what you see, try setting to daylight white balance. THis will show you the differences in colour for each beam.[/QUOTE]

the reality of life... 50% +/- of it will be in darkness(unless you have a light!) dba - compare lights

Re: CRI difference?

WOW... the difference is astonishing to say the least....

Originally Posted by Swedpat

Last week I received my two purple Maglites, a 2D and a 3D. These are not really the same colour, because Maglite has at least two different shades of purple, and I got one of each. When looking at them under cool LED-light they appear as very identical. But under incandescent light like the home light bulbs and MagCharger the difference is significant. Look at these two photos and you will see it clearly.
Also I later compared with my EagleTac M2XC4 neutral white, and the difference was significant compared to P7 LED, but not that significant as with MagCharger.
I understand this remarkable difference is an example of the difference of CRI? Edit: at request I also took a picture with EagleTac M2XC4 neutral white as light source. This actually made me surprised. The difference of the photo is much less than what I actually experience with my eyes.According to the photo it's closer to the cool white LED, but according to my LIVE view it's closer to the incan...Anyway; incandescent light is superior when it comes to true colour rendition!

Re: Cool White vs Neutral white

yah, that one is another "doesn't look like that in person" pics

not sure what is going on, why that one came out so different, and or wonder if the diffuser skews thing a bit as the M6 HO doesn't look that yellow either (new cells) compared to the others - I'll recheck settings...
try again later...

in search of ... the holy grail...

Originally Posted by xenonk

Looks like a substantial improvement with the warm/neutral emitters.
That M2C4 CW, though...

the reality of life... 50% +/- of it will be in darkness(unless you have a light!) dba - compare lights

Re: Cool White vs Neutral white

Originally Posted by Moonshadow

Very interesting. The H60 (first column) looks by far the most natural to me, and the three warm ones seem to have a very orangey colour cast.

Another vote for the H60. I like the way the warm/neutral tints bring out the reds in the magazine, but I'm not thrilled about their off-white color balance. If you could combine their red rendition with the color balance of the H60, IMO that would be perfect.

Re: Cool White vs Neutral white

um, no that's the problem... between my camera and the color output from the different LED (plus of course your and my monitor color settings, and when it was last calibrated - mine has never been calibrated) - what you see is what I got (no image manipulation).
my wall paint color (ivory white) is closer to what is seen in column 5 (on my monitor).

Originally Posted by Moonshadow

Very interesting. The H60 (first column) looks by far the most natural to me, and the three warm ones seem to have a very orangey colour cast. Looks like I'll be sticking to cool tints.

Are the walls in that corridor really painted a light orange ?

Last edited by lebox97; 09-24-2009 at 09:08 AM.
Reason: tiepo

the reality of life... 50% +/- of it will be in darkness(unless you have a light!) dba - compare lights

Re: Cool White vs Neutral white

Of late, I have been wondering why I don't seem to see many lights between 5000-6000k since that's where daylight is, and to me since I'm seeing most things in daylight, I'd like to have my flashlights be daylight-like tinted as well. Tints which come to mind would be WJ... or if you like warmer/cooler, either 3A or WD.

However, I haven't seen to have seen these tints in many flashlights.. and rather only further away from daylight, i.e. WC and 5A (at least it seems to me)

Re: Cool White vs Neutral white

Originally Posted by hoongern

Of late, I have been wondering why I don't seem to see many lights between 5000-6000k since that's where daylight is, and to me since I'm seeing most things in daylight, I'd like to have my flashlights be daylight-like tinted as well. Tints which come to mind would be WJ... or if you like warmer/cooler, either 3A or WD.

However, I haven't seen to have seen these tints in many flashlights.. and rather only further away from daylight, i.e. WC and 5A (at least it seems to me)

October 1st, 2009 Color is normally thought of as a fundamental attribute of an object: a red Corvette, a blue lake, a pink flamingo. Yet despite this popular notion, new research suggests that our perception of color is malleable, and relies heavily on biological processes of the eye and brain.

The brain's neural mechanisms keep straight which color belongs to what object, so one doesn't mistakenly see a blue flamingo in a pink lake. But what happens when a color loses the object to which it is linked? Research at the University of Chicago has demonstrated, for the first time, that instead of disappearing along with the lost object, the color latches onto a region of some other object in view - a finding that reveals a new basic property of sight. [...]